For a while now, I'm starting all my projects sketching in pencil, really small thumbnails, it helps to keep it simple, quickly, focusing only in shapes and composition. These ones are only for me, to develop later the ones I like the most.

Once I have the general ideas, I start to search for references, I look for everything that would help me, in this case, a lot of NASA pictures, robotics, mech designs, drones, etc, Best tool for that: Pinterest ;)

Then I jump right into the color sketches for the clients. I'm trying to be more conscious about colors than I used to when I worked in black and white before the colors. Once I establish my main palette I'll try to keep it through the whole process.

The art director choose C. And it's time to start the fun part! From here, there isn't much to do other than start detailing the piece, I had already established the values and colors in the sketch stage. So it's really straightforward from here on.